pocketmine\utils\Binary::writeInt PHP Method

    public static function writeInt($value)
    {
        return pack("N", $value);
    }

 public function handle($address, $port, $packet)
 {
     $offset = 2;
     $packetType = ord($packet[$offset++]);
     $sessionID = Binary::readInt(substr($packet, $offset, 4));
     $offset += 4;
     $payload = substr($packet, $offset);
     switch ($packetType) {
         case self::HANDSHAKE:
             //Handshake
             $reply = chr(self::HANDSHAKE);
             $reply .= Binary::writeInt($sessionID);
             $reply .= self::getTokenString($this->token, $address) . "";
             $this->server->getNetwork()->sendPacket($address, $port, $reply);
             break;
         case self::STATISTICS:
             //Stat
             $token = Binary::readInt(substr($payload, 0, 4));
             if ($token !== self::getTokenString($this->token, $address) and $token !== self::getTokenString($this->lastToken, $address)) {
                 break;
             }
             $reply = chr(self::STATISTICS);
             $reply .= Binary::writeInt($sessionID);
             if ($this->timeout < microtime(true)) {
                 $this->regenerateInfo();
             }
             if (strlen($payload) === 8) {
                 $reply .= $this->longData;
             } else {
                 $reply .= $this->shortData;
             }
             $this->server->getNetwork()->sendPacket($address, $port, $reply);
             break;
     }
 }